Dry working photographic process utilizing a non-silver photosensitive composition



United States Patent 3,533,792 DRY WORKING PHOTOGRAPHIC PROCESS UTI-LIZING A NON-SILVER PHOTOSENSITIVE COMPOSITION Victor P. Petro,Brecksville, James M. Lewis, Cleveland, and Eugene Wainer, ShakerHeights, Ohio, assignors to Horizons Incorporated, a division ofHorizons Research Incorporated, a corporation of Ohio No Drawing. FiledDec. 26, 1967, Ser. No. 693,178 Int. Cl. G03c l/00, 1/72 U.S. CI. 96-4817 Claims ABSTRACT OF THE DISCLOSURE The invention herein described wasmade in the course of or under a contract or subcontract thereunder,with The Systems Engineering Group, Air Force Systems Command.

This invention relates to completely dry working photography. Moreparticularly, it relates to compositions which are sensitive to lightand which are suitable for photography and photographic reproductionpurposes and to the production of stable, colored, print-out, anddevelopable-out images produced by exposing such compositions to lightand/or to light and heat.

The invention relates to control of the density and contrast of theimage by suitably adjusting the radiation to which the composition isexposed.

The present invention relates to the addition of one or more compoundsto the compositions of the kind described in United States patentapplication Ser. No. 603,- 731 filed Dec. 22, 1966, in order to produceimages of any desired color, including jet black.

A specific object of this invention is to provide a photographiccomposition yielding a black or near neutral image as the result of theapplication of heat to said composition after it has beenphotographically exposed.

With the exception of color photographic printing or where a specificcolored image is desired for display purposes, virtually every practicalapplication of presently known free radical photographic systems prefera black or near black image color. Such contemplated uses include:ofiice photocopy; microfilm retrieval systems; photographic printing,e.g., portraiture proofing; and even such military uses as themultigeneration aerial reconnaissance printing described in PhotographicScience and Engineering, vol. IX, No. 2, pp. 133-137, 1965; and all suchuses demand a suitable black image produced without recourse to wetprocessing.

Furthermore, this invention relates to the control of and the variationof the color of the image by the addition of specific chemicals to thecompositions of the invention. As a result of the ability to control thecolor produced, a near neutral (black to blue black) image can beachieved.

Briefly it has been found that photosensitive compositions based on thesingle dye former 1,1-bis-(p-dimethylaminophenyl)ethylene, having thestructure Patented Oct. 13, 1970 C53 (Fl/H2 CH3 O om CH3 such as thosedescribed in patent application Ser. No. 603,731 filed Dec. 22, 1966,can be altered by the addition of suitable color complexes so that thecolor normally obtained with this compound, i.e. greenish-blue, can beso altered as to form a neutral or black color.

As a consequence, it is not necessary to use a combination of dyeprecursors, each of which would add the appropriate absorption in thevisible end of the spectrum, i.e. yellow, cyan and magenta, as to obtaintotal visible saturation. The main objection to the use of a combinationof dye precursors is that normally it is extremely difiicult to obtaindye precursors of the yellow, cyan and magenta which when activated withthe appropriate organic halide will react photochemically at the samerate in order to achieve the desired total saturation in the visible. Inthe usual case, almost without exception, there are notable absences inthe visible spectrum. In addition, when the appropriate combination ofdye precursors can be found, a very delicate balance as well as a highdegree of purity of these materials must be maintained in a coating mixin order to ensure the correct color balance.

The present invention eliminates many of these ditficulties by the useof only one photoactive dye former in the photosensitive composition.The additives used to pro duce the desired color balance do notparticipate or influence the photochemical reaction, but becomeeffective only when the material is being fixed. During the fixing stagethe additive(s) interact with the dye salt formed during thephotochemical steps to produce the desired color. It has been shown thatby employing this technique that red, blue and green or any combinationof these colors can be produced.

The neutral image, dry working characteristics of the compositionsherein described are particularly important in certain of the aboveuses, since the use of a wet working system in high speed aircraft orspace vehicles is almost inconveivable. One such use whose feasibilityhas been established is the preparation of multigeneration printing ofaerial reconnaissance negatives as described in the above notedpublication. When a military recon naissance aircraft photographs atarget, the negative resulting from that photograph is developed andreproduced through as many as four generations for determination of theintelligence revealed in the photograph. The original negative isprinted only once and then is stored in the archives. All subsequentprints are made from the second generation prepared from the originalnegative. Conventional silver halide systems are not completely suitablefor this multigeneration printing purpose, since the image is granular(particulate) and consequently each subsequent generation losesinformation which may be valuable in strategic decisions made from theuse of these photographs. Free radical photosystems being molecularrather than granular have almost unlimited resolution particularly whencoated in thin layers (about 4 to 5 microns thick), to take advantage ofthe geometry of present printer processors and their light sources. Freeradical photographic systems have been established to be an excellentmedium for these multigeneration aerial reconnaissance printing,especially photosensitive free radical compositions based on theteachings of U.S. Pat. 3,109,736 and described in Photographic Scienceand Engineering, vol. IX, No. 2, pp. 133437, for March and April 1965,under the title New Photographic Process, No. 4, The Cyanine Base FreeRadical Photosystem-A Panchromatic Black Image High Resolution PrintoutFilm. The compositions described yield excellent jet black images and 3retain high latitudes multigeneration printing through four generations,with the minimum loss of intelligene. However, the compositions are notdry working, but require a solvent rinse after exposure to render theimage fixed and stable to ambient light.

Photointerpreters who evaluate these aerial reonnaissance photographstraditionally have been schooled in the use of black image materials andare reluctant to use other colors. Hence the need for a dry workingblack image system to be used for aerial reconnaissance multigenerationprinting.

As described in US. patent application Ser. No. 603,731, one preferredcomposition from which hand coatings were made at .0015 inch wetthickness on raw polyester film and thereafter evaluated as indicatedbelow consisted of the following:

50 mg. 1,1-bis (p-dimethylaminophenyl)ethylene 1 200 mg. iodoform 5 mg.4-picoline-1-oxide 25 mg. 2,6-di-t-butyl-p-cresol mg. triphenylstibine 3cc. polystyrene 10% in benzene 1cc. acetone 1 cc. benzene The presentinvention is based on the addition of one or more specific compoundsfrom certain clases of compounds to the formulation described in theabove noted application in order to produce variations in the hue orcolor of the final image.

The compositions described in the examples which, follow are eachprepared by bringing the several constituents together in a suitablesolvent system under a safelight or in total darkness and, afterthoroughly mixing the composition, applying it to a solid substrate suchas baryta paper or a film of polyester, glass or other suitable support.

After the composition has been laid down as a thin film, it is permittedto dry in air, in the dark, or under a safelight, and then it isphotographically exposed to the equivalent of 0.01 Watt second/cmfi.After exposure of this material, the latent image is developed byexposing the film to radiant energy of an appropriate intensity (1.5 to3.0 kw.) and suitable wavelength (600-800 m for a period of time in therange 1 second to 40 seconds. The film sample is then heat fixed at 135C.-150 C. in moving air for 2-5 minutes; whereby a very stable denseblack image is observed in the exposed areas.

With this amount of photographic exposure, maximum density of about1.5-2 is achieved and the heated film is completely fixed, i.e. theimage and background do not change upon further exposure to light.Increasing the photographic exposure to the equivalent of 0.1 wattsecond/cm. and developing gave maximum densities in excess of 2.0 in the14th step of a 21 step tablet. The density of the resulting visibleimage is readily varied by the dose of radiation utilized in eitherexposure step of the process.

In general, images having a desired color are produced by exposingphotosensitive compositions of this invention to a pattern of radiantenergy and then developing and intensifying the image produced as aresult of said photographic exposure by exposing the entire compositionto a radiant energy of between 600 and 800 mg.

The process may include, in addition, the step of fixing the image byheating the image-containing material to between 120 C. and 160 C. for ashort interval of time.

With exposures of at least about 1 watt second per square centimeter, adirect printout image is obtained. With exposures of substantially lessthan 1 watt second per square centimeter, a latent image is producewhich is 1 Structure then developed by a subsequent exposure to asuitable dose of radiation.

The following examples will serves to further illustrate the invention,the compounds being listed in the order in which they are added to theformulation, in a solution of suitable solvents.

EXAMPLE 1 By using a compound containing an SH group, attached to analkyl, aryl, aralkyl or other monovalent group of the type hereinafterdescribed, a blue image is obtained. One preferred formulation is asfollows:

mg. 1,1bis-p-dimethylaminophenyl ethylene 50 mg. 2,6-di-t-butyl-p-cresol10 mg. 2-mercaptoacetanilide 5 mg. 4-picoline-N-oxide 10 mg.triphenylstibine 200 mg. iodoform 3cc. 10% polystyrene in benzene Otherformulations yielding a blue image are those in which themercaptoacetanilide utilized by way of eX ample in the above formulationwas replaced with similar amounts of any of the following RSH compoundsin which R is shown to be an alkyl, aryl, or hetero group which may besubstituted or unsubstituted.

or other aryl, alkyl, etc. compounds with an SH group.

EXAMPLE 2 By utilizing a pyrazolone instead of the mercapto compound ofExample 1, a red to violet image was obtained with the followingformulation:

100 mg. 1,1-bis-pdimethylami-nophenyl ethylene 5-10 mg. l-phenyl-S-aminopyrazol-S-one 50 mg. 2,6-di-t-butyl-p-creso1 5 mg. 4-picoline-N-oxide 10mg. triphenylstibine 200 mg. iodoform 3 cc. 10% polystyrene in benzeneRed to violet images were obtained with similar formulations in whichthe following compounds containing the ring were used in place of the1pheny1-3amino-pyrazol-S- one:

3-methyl-5-pyrazolone 1-(3'-amino benzene)3-methyl-5-pyrazolone1-(4'-amino benzene)-3-methyl-5-pyrazolone 1-(2'-chlorobenzene)-3-methyl-S-pyrazolone l-(3-chlorobenzene)-3-methyl-5-pyrazolone 1-(4'-chlorobenzene)-3-methy1-5-pyrazolone1-(2',5'-dichlorobenzene)-3-methyl-5-pyrazolone1,3-diphenyl-5-pyrazo1one 1-(4'-methylbenzene)-3-methyl-5-pyrazolone1-phenyl-3-methyl-5-pyrazolone Bis-pyrazolone of the structure 11 II R cl t e lt I i /o lil 0 /r -r I I EXAMPLES The following formulationproduces a green image when processed in the previously describedmanner.

100 mg. 1,l-bis-p-dimethylaminophenyl ethylene 50 mg. acetoacetanilide50 mg. 2,6-di-t-butyl-p-cresol 10 mg. triphenylstibine mg.4-picoline-N-oxide 200 mg. iodoform 3 cc. polystyrene Other compoundswhich have been found to produce a green image when used in place of theacetoanilide in example include the following anilides:

Acetoacet-Z,S-dichloroanilide Acetoacet-2,5-diethoxy-4-chloroanilideAcetoacet-2,4-dimethoxy-S-chloroanilideAcetoacet-Z-methyl-3-chloroanilide Acetoacet-2-methyl-4-chloroanilideAlthough the exact mechanism is not known whereby the additions of theseveral classes of compounds produces a change in the color of theimage, it appears possible that the dimethylaminophenyl substitutedethylene contributes to the formation of a black or near neutral imagewhen acted on by the products which result when the iodoform andacetanilide and/or pyrazolone are exposed to a suitable dose of radiantenergy.

Instead of the vinyl C CH group in this compound, compounds in which oneor both of the hydrogens are replaced by an alkyl or aryl group could beutilized.

It will be evident that other compounds may be used in place of each ofthe several constituents in the formula Without departing from theinvention, especially since the equivalency of these are described in anumber of issued patents already issued to applicants assignee.

For example, triphenylstibine may be replaced with triphenylbismuthine,triphenylphosphine or triphenylarsine; polystyrene may be replaced withpolycarbonates or other synthetic film-forming resins; and the iodoformmay be replaced by other compounds in which at least three halogen atomsare attached to a single terminal carbon atom in an organic compound.Such organic halogen compounds are represented by the general formulaA-CQ wherein each Q represents a halogen atom selected from the groupconsisting of Cl, Br and I and A represents a monovalent member selectedfrom the group consisting of H, Cl, Br, I, alkyl, substituted alkyl,particularly halogen substituted alkyl, aryl, aroyl and sub stitutedaryl.

It is also possible to include both an acetanilide and a pyrazol-S-onein the same formulation, as shown by the following example.

EXAMPLE 4 A typical formulation producing a near neutral image is:

100 mg. l,l-bis-p-dimethylaminophenyl ethylene 50 mg.2,6-di-t-butyl-p-cresol 10 mg. 1-phenyl-3-amine-pyrazol-5-one 10 mg.Z-mercaptoacetanilide 5 mg. 4-picoline-N-oxide 10 mg. triphenylstibine200 mg. iodoform 3 cc. 10% polystyrene in benzene Although only a few ofthe many color-forming additives found to produce blue, red to violet orgreen colored images are listed above, the following general formulasdescribe classes of compounds which produce the indicated colored imagewhen processed as in the preceding examples and Which do not diffuseappreciably through the sensitive film.

Blue image I? QN-e-omsrr Red to violet image oo II I N o=o Green image Ho H o l II I II N-N-C-C-CHs 1% X X is a long chain alkyl, such asoctadecyl or heptadecyl. The photosensitive compositions above describedmay produce either a direct printout image or a latent image dependingon the amount of energy utilized in the exposure step. A latent image isproduced by an exposure of approximately 0.1 watt second per squarecentimeter. When approximately ten times as much energy, i.e. about 1watt second per square centimeter, is utilized in the exposure step, adirect printout image results. It has been observed that the color ofthe final image produced as a direct printout is not always the same asthat which results when the latent image is later developed from anotherwise similar composition. Other compounds having a vinyl group maybe utilized in place of the 1,l-bis(p-dimethylaminophenyl)ethylene. Forexample, each of the following has been found to be suitable in thepresent invention:

in which A represents benzyl; naphthyl or diphenyl; X and Y are each Hor alkyl (particularly methyl or ethyl); and R and R are each H, alkylor aryl.

It should also be understood that by the use of mix tures of the colorforming constituents it is possible to obtain a black image instead ofthe colors previously described.

The compositions may include, as additional constituents which enhancethe formation of the desired image, any one or more of the following:picoline-loxides; triaryl compounds of P, Sb, As or Bi; and cresols suchas 2,6-di-tert-butyl-cresol.

Having now described the invention in general terms, it is not intendedthat it be limited except by the claims which follow.

We claim:

1. A photosensitive composition consisting essentially of the following:

(a) one or more dye-forming compounds represented by the general formulaRl-O-R2 ll Ra \R4 wherein R and R are each a monovalent radicalrepresented by the formula in which A is selected from the groupconsisting of benzyl, naphthyl and diphenyl, and in which X and Y areeach selected from the group consisting of H and alkyl and wherein R andR are each selected from the group consisting of H, alkyl and aryl;

(b) one or more organic halogen compounds in which at least threehalogen atoms selected from the group consisting of Cl, Br and I areattached to a terminal carbon in an alkane or aryl alkane compoundrepresented by the general formula ACQ wherein Q represents a halogenselected from the group consisting of Cl, Br and I and A represents amonovalent member of the group selected from H, Cl, Br, 1, alkyl,substituted alkyl, aryl, aroyl, and substituted aryl; and

(c) at least one compound which forms a colored image when reacted withthe compounds of group (a) above, said colored image forming compoundsbeing selected from the group consisting of thiols, pyrazolones andacetoanilides and mixtures of said compounds.

2. The composition of claim 1 including at least one additional compoundwhich enhances the formation of the desired image and which is selectedfrom the group consisting of picoline-l-oxides; triaryl compounds of P,Sb, As or Bi; and tertiary cresols.

3. The composition of claim 1 wherein the dye forming compound is1,1-bis-dimethylaminophenyl ethylene.

4. The composition of claim 1 wherein the organic halogen compound isiodoform.

5. A composition according to claim :1 wherein the image which printsout is blue and the thiol is a mercapto compound represented by theformula RSH wherein R represents alkyl, aryl or hetero groups,substituted or unsubstituted.

6. A composition according to claim 1 wherein the image which prints outis red to violet and the composition contains1-phenyl-3-amino-pyrazo1-5-one.

7. A composition according to claim 1 in which both an acetanilide and apyrazolone are present, whereby a near neutral image is obtained.

8. A composition according to claim 1 containing in addition afilm-forming resinous binder for the constituents of the composition sothat it may exist as a thin film.

9. A composition according to claim 1 comprising 1,1-bis-p-dimethylaminophenyl ethylene; 2,6-di-t-butyl-p-cresol;Z-mercaptoacetanilide; 4-picoline-N-oxide; triphenylstibine; andiodoform.

10. A composition according to claim 1 comprising1,l-bis-p-dimethylaminophenyl ethylene; 1-phenyl-3-amino pyrazol-S-one;2,6-di-t-butyl-p-cresol; 4-picoline-N-oxide; triphenylstibine; andiodoform.

11. A composition according to claim 1 comprising1,l-bis-p-dimethylaminophenyl ethylene; acetoacetanilide;2,6-di-t-butyl-p-cresol; triphenylstibine; 4-picoline-N-oxide; andiodoform.

12. A composition according to claim 1 comprisingl,1-bis-p-dimethylaminophenyl ethylene; 2,6-di-t-butyl-pcresol;1-phenyl-3-amino-pyrazol-5-one; Z-mercaptoacetanilide;4-picoline-N-oxide; tn'phenylstibine; and iodoform in a film formingbinder.

13. A composition according to claim 1 in which a mixture of compoundsunder (c) is utilized to produce a black image.

14. A process for producing an image having a desired color whichcomprises exposing a photosensitive composition according to claim 1 toa pattern of radiant energy and then developing and intensifying theimage produced as a result of said photographic exposure by exposing theentire composition to radiant energy of between 600 and 800 my 15.Process of claim 14 including in addition, the step of fixing the imageby heating the image containing composition to between C. and C. for ashort interval of time.

16. A process according to claim 14 in which the exposure is at leastabout 1 watt second per square centimeter whereby a direct printoutimage is obtained.

17. A process according to claim 14 wherein the exposure issubstantially less than 1 watt second per square centimeter and a latentimage is produced which is then developed by a subsequent exposure to asuitable dose of radiation.

References Cited UNITED STATES PATENTS 3,102,029 8/1963 Fichter et a196-48 X 3,390,996 7/1968 MacLachlan 96-48 3,436,353 4/1969 Dreyer et al96-90 3,481,739 12/ 1969 Wainer et al. 96-90 3,484,238 12/ 1969 Fox96-88 WILLIAM D. MARTIN, Primary Examiner W. R. TRENOR, AssistantExaminer US. Cl. X.R. 96-88, 90, 115

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 53379 2 Dated Oct. 11. 1970 ln ent fl Victor P. Petro et a1 It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, lines 1-4; correct the structural formula to read:

CH2 CH CH Q 1/ 3 CH3 \CH3 Column 3, line 1; after "latitudes" insert-for Column 3, line 2; correct -intelligence- Column 3, lines 37-41;delete the strucutral formula Column 3, last line; after "stru'zz'tureinsert (CH TLQ- 00M (CH 2 Column 4, line 12; insert parenthesis to read:1,1-bis- (p-dimethylaminophenyl) ethylene Column 4, line 25; after"unsubstituted insert a colon Column 4, line 55,- insert parenthesis toread: l,l-his- (p-dimethylaminophenyl)ethylene UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent 3.533.792 Dated October 13. 1970Invent fl Victor P. Petro et al PAGE 2 It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 4, line 65; correct the formula to read:

Column 5 line 14; after the structural formula; insert --of the typedescribed in United States Patent 2 ,294,909.--

Column 5, line 25; after "polystyrene" insert in benzene- Column 5, line73; insert parenthesis to read: l,lbis (p-dimethylaminophenyl) ethyleneColumn 6 lines 15-19 correct the formula to read:

X Column 6 lines 21-25, correct the formula to read:

fi C N to UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent33531702 Dated Oct 13 1970 PAGE 3 Inventor(s) Victor P. Petro et a1 Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 6, lines 27-31, correct the formula to read:

Q$ljim In line 2 of claims 3, 9, 10, 11 and 12, insert parenthesis toread --1,1bis (dimethylaminophenyl)ethylene-- Signed and sealed this 6thday of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents FORM P0405) (@591 uscoMM-oc scan-Pu is.GOVIIKIINT PIIII'IIIG OF'iCE: III. 0-3-1

